---
name: "Protocol::HTTP2"
section: "3pm"
platform: "linux"
package: "libprotocol-http2-perl"
version: "1.11-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Protocol::HTTP2"
---

# Protocol::HTTP2(3pm)

HTTP/2 protocol implementation (RFC 7540)

## NAME

Protocol::HTTP2 - HTTP/2 protocol implementation (RFC 7540)

## SYNOPSIS

```
    use Protocol::HTTP2;
    # get protocol identification string for secure connections
    print Protocol::HTTP2::ident_tls;           # h2
    # get protocol identification string for non-secure connections
    print Protocol::HTTP2::ident_plain;         # h2c
```

## DESCRIPTION

Protocol::HTTP2 is HTTP/2 protocol implementation (RFC 7540 \<https://tools.ietf.org/html/rfc7540\>) with stateful decoders/encoders of HTTP/2 frames. You may use this module to implement your own HTTP/2 client/server/intermediate on top of your favorite event loop over plain or tls socket (see examples).

## STATUS

Current status - beta. Structures, module names and methods seems like stable. I've started this project to understand internals of HTTP/2 and may be it will never become production, but at least it works.

```
    | Spec                    |      status     |
    | ----------------------- | --------------- |
    | Negotiation             |   ALPN, NPN,    |
    |                         | Upgrade, direct |
    | Preface                 |        +        |
    | Headers (de)compression |        +        |
    | Stream states           |        +        |
    | Flow control            |        ±        |
    | Stream priority         |        ±        |
    | Server push             |        +        |
    | Connect method          |        -        |
    | Frame           | encoder | decoder |
    | --------------- |:-------:|:-------:|
    | DATA            |    ±    |    +    |
    | HEADERS         |    +    |    +    |
    | PRIORITY        |    +    |    +    |
    | RST_STREAM      |    +    |    +    |
    | SETTINGS        |    +    |    +    |
    | PUSH_PROMISE    |    +    |    +    |
    | PING            |    +    |    +    |
    | GOAWAY          |    +    |    +    |
    | WINDOW_UPDATE   |    +    |    +    |
    | CONTINUATION    |    ±    |    +    |
```

- \- -- not implemented

  - ± -- incomplete

  - \+ -- implemented (may even work)

  ## MODULES

### Protocol::HTTP2::Client

Client protocol decoder/encoder with constructor of requests

### Protocol::HTTP2::Server

Server protocol decoder/encoder with constructor of responses/pushes

### Protocol::HTTP2::Connection

Main low level module for protocol logic and state processing. Connection object is a mixin of Protocol::HTTP2::Frame (frame encoding/decoding), Protocol::HTTP2::Stream (stream operations) and Protocol::HTTP2::Upgrade (HTTP/1.1 Upgrade support)

### Protocol::HTTP2::HeaderCompression

Module implements HPACK - Header Compression for HTTP/2 (RFC 7541 \<https://tools.ietf.org/html/rfc7541\>).

### Protocol::HTTP2::Constants

Module contains all defined in HTTP/2 protocol constants and default values

### Protocol::HTTP2::Trace

Module for debugging. You can setup HTTP2\_DEBUG environment variable to change verbosity of the module (output to STDOUT). Default level is error.

```
    $ export HTTP2_DEBUG=debug
    $ perl ./http2_program
```

## SEE ALSO

\<https://github.com/vlet/p5-Protocol-HTTP2/wiki\> - Protocol::HTTP2 wiki

\<http://http2.github.io/\> - official HTTP/2 specification site

\<http://daniel.haxx.se/http2/\> - http2 explained

## LICENSE

Copyright (C) Vladimir Lettiev.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

## AUTHOR

Vladimir Lettiev \<thecrux@gmail.com\>